In the proposed one-year extension, it is planned to synthesize ten to fifteen new agents with functional groups selected for effective iron binding, in accordance with the objectives of the original proposal. The new chelators willbe characterized and submitted for testing on experimental animals. The proposed new chelating agents will contain phenol, catechol, and hydroxamic acid groups in new structures, and in combinations with auxiliary groups such as aminocarboxylate functions. Other promising modifications of these chelators such as esterification, use of the pyridoxyl ring, and macrocyclic and cryptate structures, will be investigated.